Abstract: A transportable nuclear power generator unit is provided. The transportable nuclear power generator unit includes a container configured to be transportable by a vehicle, and nuclear power module disposed inside the container. The nuclear power module includes a sealed pressure vessel and a nuclear core disposed inside the sealed pressure vessel. The transportable nuclear power generator unit also includes a plurality of radiation shields provided at a plurality of interior walls inside the container to surround the sealed pressure vessel. The radiation shields are configured to shield radiation generated by the nuclear power module. The radiation shields include a movable shield configured to be movable between a position inside the container and a position on an exterior wall of the container.

Abstract: An animal house includes an impermeable hollow-moulded structure having at least one convex surface. The structure includes a first flat surface extending in a first direction and a second flat surface extending in a second direction. The convex surface connects the first flat surface to the second flat surface. The structure further includes a rib defining a sharp edge. The rib is configured to be releasably attached proximate to or on the convex surface such that the rib diverts a liquid flowing over the convex surface away from the structure. An impermeable hollow-moulded panel with protruding ridges is also provided to prevent water ingress.

Abstract: A SIL monopulse radar includes a self-injection-locking oscillator (SILO), a transmit antenna, two receive antennas, a hybrid coupler, a first demodulator, a second demodulator and a processor. The transmit antenna transmits the oscillation signal of the SILO to object. The two receive antennas receive a reflected signal from the object as a first echo signal and a second echo signal. The hybrid coupler outputs a difference signal and a sum signal. The difference signal is injected into the SILO. The first demodulator frequency-demodulates the oscillation signal to produce a first demodulated signal. The second demodulator phase-demodulates the sum signal by using the oscillation signal as a reference signal to produce a second demodulated signal. The processor processes the first and second demodulated signals to produce a monopulse ratio signal. The SIL monopulse radar can identify the posture and motion of a human body by analyzing the monopulse ratio signal.

Abstract: A liquid-metal-cooled nuclear reactor includes a main vessel containing a primary fluid and a cylindrical separation structure, separating a hot leg from a cold leg. The cold leg encompasses the hot leg. At least one opening is provided in the cylindrical separation structure to enable the primary fluid to flow from the cold leg to the hot leg. A core is submerged in the hot leg. The reactor also includes at least one heat exchanger having an inlet from the hot leg and an outlet to the cold leg for transferring heat from the primary fluid to a secondary fluid of an externally connecting circuit. A reactor lid covers the main vessel. A gas plenum is disposed beneath the reactor lid and above the hot leg. An inner lid is disposed beneath the reactor lid covering the cold leg. The hot leg is open ended towards the gas plenum.

Abstract: A fuel salt shipping system includes an outer container defining an outer containment volume and an inner container disposed within the outer containment volume, with the inner container defining an inner volume configured to contain a molten fuel salt. The inner container and the outer container cooperate to define an annulus region therebetween. The fuel salt shipping system further includes a fuel salt conduit penetrating the outer container and the inner container and fluidically coupling the inner volume to an external environment of the system. The fuel salt shipping system further includes a heating system including a heater disposed in the annulus space and configured to impart a heat output to the molten fuel salt of the inner volume and change a phase of the molten fuel salt held therein from a solid phase to a liquid phase.

Abstract: A crab snare apparatus that is adapted to breakaway cleanly from the crab's grip without disturbing the crab's position over the snare loops, thereby making the snaring of crabs more certain.

Abstract: A method is for monitoring a nuclear reactor comprising a core in which fuel assemblies are loaded, each assembly comprising nuclear fuel rods each including nuclear fuel pellets and a cladding surrounding the pellets. The method includes determining (100) at least one operating time limit (TFPPI) for the extended reduced power operation of the reduced power nuclear reactor, so as to avoid a rupture of at least one of the claddings, operating (102) the nuclear reactor at reduced power for an actual time strictly less than the time limit (TFPPI), and relaxing (104) at least one threshold for protecting the nuclear power plant as a function of a difference between the time limit (TFPPI) and the actual time.

Abstract: A nuclear reaction generator includes a chamber configured to contain a gas and including a target. The nuclear reaction generator also includes a filament provided inside the chamber and a voltage source configured to apply a first positive voltage to the filament relative to the chamber. The first positive voltage is configured to heat the filament to a temperature at which thermionic emission occurs and a plurality of thermions are generated, and the plurality of thermions is configured to ionize the gas to generate positive ions in the chamber. The target is configured such that nuclear reactions occur when the positive ions interact with the target.

Abstract: A nuclear reactor control assembly includes a reactivity control device comprising a control rod cluster and a drive rod. The control rod cluster comprises an attaching head. The drive rod comprises an attaching device for connecting the drive rod to the attaching head. The attaching device is movable between a connection position and a disconnection position. The drive rod and the attaching device define an axial trough recess forming a sleeve. A checking device is used for checking separation between the control rod cluster and the drive rod. The checking device comprises a probe rod which is free to move translationally in the sleeve. A lower end of the probe rod can abut the attaching head. Relative displacement of the probe rod with respect to the drive rod can be used to determine whether the drive rod is separated from the control rod cluster.

Abstract: Disclosed are a voltage drop measurement system and methods for measuring resistivity of a nuclear reactor cladding. The system includes a short cladding sample of a nuclear reactor cladding. Two electrically conductive plugs are attached to the short cladding. A power supply is electrically coupled to the each of the two electrically conductive plugs and is configured to apply an electrical current to the short cladding through the two electrically conductive plugs. Two needle like probes are electrically coupled to a surface of the short cladding between the two electrically conductive plugs. The needle like probes are spaced apart by a distance L. Resistivity and heat flux are determined in accordance with Equations (1)-(4).

Abstract: There is disclosed a containment system for a nuclear plant, the containment system comprising a pressure vessel defining a containment space for containing nuclear plant structures, a working floor extending from within the containment space to outside the pressure vessel, an access opening in the pressure vessel for providing access from the working floor outside the pressure vessel to the working floor in the containment space, and an access door provided within the pressure vessel. The access door is configured to slidably move downwardly with respect to the pressure vessel from a closed position in which it closes the access opening to seal the pressure vessel, and an open position in which it reveals the access opening and is received in a door space in the working floor.

Abstract: A nuclear reactor assembly may include a fuel rod and an end plug extending from the fuel rod The end plug may include a first engagement surface and a second engagement surface. The second engagement surface may have a circular groove disposed in an exterior surface of the end plug, the circular groove defining a plane orthogonal to a longitudinal axis of the end plug. The assembly may also include a bottom nozzle forming a recess, in which the recess includes a first retainer extending from the recess and a second retainer extending from the recess. The first retainer may engage the first engagement surface and the second retainer may include a second retainer portion to engage the second engagement surface. The first retainer and the second retainer may axially retain the end plug to the bottom nozzle.

Abstract: Fissile target materials are provided. The fissile target materials can include a target substrate and a capturing layer operably interfacing with at least one surface of the target substrate. Fission fissile target materials are also provided that can include a target substrate comprising at least one fissile atom and a capturing layer operably interfacing with at least one surface of the target substrate. The capturing layer can include at least one fission product.

Abstract: The present application relates to nuclear fuel claddings, and more particularly to zirconium alloy tubes with a ceramic covering. A first coating layer is applied to the ceramic covering. A second coating layer is over the first coating layer. The first coating layer includes Nb. The second coating layer includes Cr.

Abstract: A method for replacing a damaged sleeve lining a tube passing through a nuclear reactor pressure vessel. The damaged sleeve has an end including a radially enlarged end portion for resting on a support section of the tube for retaining the damaged sleeve in the tube. The method includes removing the damaged sleeve from a tube; providing a sleeve assembly including a first sleeve with a radially variable end and a retainer; installing the sleeve assembly in the tube so the radially variable end of the first sleeve is received by the support section, the radially variable end being in a radially contracted configuration during installation and being in a radially expanded configuration after the sleeve assembly is installed in the tube; and deforming the retainer from an installation configuration to a retention configuration to retain the radially variable end of the first sleeve in the radially expanded configuration.

Abstract: A container holds radioactive material. A sub-criticality controller protects the radioactive material from reaching a criticality from contact with the water. The sub-criticality controller includes a metallic composition having at least one metal component and at least one borate component bonded to the at least one metal component. The metallic composition forms a new borate that absorbs neutrons when the metallic composition contacts water in the case of an incident.

Abstract: An automatic leveling type maintenance platform for a high-temperature gas cooled reactor is provided. A floating plate is automatically leveled by using a leveling liquid. During leveling, only a water driving assembly needs to be controlled to drive a housing to be close to an inner bottom surface of a liquid storage container. A sliding block assembly and a lifting guide mechanism are controlled to be locked and fixed after the floating plate is leveled. The floating plate can allow for automatic and rapid leveling and locking operation. Thus, complex and time-consuming fine adjustment control does not need to be performed. Also, when the platform is used in a spherical top cap of a pressure vessel of the reactor for a maintenance operation, then support legs of a support assembly do not need to have telescopic motion.

Abstract: A method of determination of a nuclear core loading pattern defining the disposition of fuel assemblies. The method includes defining at least one potential core loading pattern and calculating predictive bowing of the fuel assemblies at the end of the operation cycle for each potential core loading pattern. The calculation is carried out by an automatic learning algorithm trained on a training data set that includes a plurality of other core loading patterns. The set also includes, for each of the other core loading patterns, measurements of bowing of fuel assemblies at the end of operation cycle. The method also includes evaluating the at least one potential core loading pattern based on the predictive bowing calculations and at least one predetermined criteria. The method further includes selecting one of the potential core loading patterns based at least in part on the evaluating.

Abstract: A nested pebble bed blanket surrounds a fusion reactor's vacuum chamber. The blanket includes stacks of nested pebbles composed of neutron multiplier shells filled with breeding spheroids. The shells have perforations passing through their inner and outer surfaces. The shells include therein perforated coolant distributor elements coupled to or unitary with the inner surfaces. Each perforated element is in line with a respective shell perforation, which allows coolant to flow into the sphere through the perforations and elements. When bombarded by neutrons, the nested pebbles produce fusion fuel to sustain fusion reactions. The coolant sweeps out the fusion fuel, and cools the breeding spheroids. Pebbles in the blanket are replenished with conveyor systems. A separator extracts the fusion fuel from the blanket coolant. Heat from the walls and the nested pebble bed is extracted by inert gases and then conveyed to a thermal storage and/or a power cycle.

Abstract: Carbide-based fuel assembly includes outer structural member of ceramic matrix composite material (e.g., SiC—SiC composite), insulation layer of porous refractory ceramic material (e.g., zirconium carbide with open-cell foam structure or fibrous zirconium carbide), and interior structural member of refractory ceramic-graphite composite material (e.g., zirconium carbide-graphite or niobium carbide-graphite). Spacer structures between various layers provide a defined and controlled spacing relationship. A fuel element bundle positioned between support meshes includes a plurality of distributively arranged fuel elements or a solid, unitary fuel element with coolant channels, each having a fuel composition including high assay, low enriched uranium (HALEU).